Self-fired heater and fan unit



Nov. 5, 1963 J. KEYES ETAL ,10 2

SELF-FIRED HEATER AND FAN UNIT Filed Nov. 5, 1961 2 Sheets-Sheet l .ZMW I'M MN I 38 If nfz eniers c 6 5, E7536 zkefl'zzy fig Lawrence I] Smffi Nov. 5, 1963 J, KEYEs ETAL 3,109,422

SELF-FIRED HEATER AND FAN UNIT Filed Nov. 5, 1961 2 Sheets-Sheet 2 I! M mi E WWI/'12 $2 Z5 2 /612 5 %dlazureme, 5mzlz W Y c M United States Patent 3,109,422 SELF-FIRED HEATER AND FAN UNIT Jack Keyes, Park Ridge, Erwin Oehlerking, Des Plaines, and Lawrence J. Smith, Oak Park, Ill., assignors to Bell & Gossett Company, a corporation of Illinois Filed Nov. 3, 1961, Ser. No. 149,894 7 Claims. (Cl. 126-110) This invention relates to a self-fired heater and fan unit for use in space heating applications and the principal object of this invention is to provide such a unit having multiple fan sections in concentric arrangement and driven by a single motor for concurrently supplying a large volume of space heating air at low pressure and a small volume of combustion air at high pressure.

Another object of the invention is the provision of a heater and fan unit employing a composite fan structure having radially displaced inner and outer fan sections rigidly interconnected and arranged for conjoint rotation with a motor shaft to provide a high volume supply of space heating air from the inner section and to provide a quiet high pressure supply of combustion air from the outer section which operates at a relatively high peripheral speed.

Still another object of the invention is the provision of a compact self-fired heater and fan unit of the above type.

Other objects and advantages will become apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a side elevational view of the self-fired heater and fan unit of this invention with portions broken away and sectioned to facilitate disclosure;

FIG. ,2 is a face view of a subassembly for housing the fan and heater units and is taken approximately on the line 22 of FIG. 1; and

FIG. 3 is a front elevation view of the unit.

Referring now to the drawings and particularly to FIG. 1 thereof, the self-fired heater and fan unit is designated in its entirety as .10 and is shown in vertical position which is preferred, as the unit preferably is suspended from the ceiling of the enclosure which it is to heat.

In general, the unit consists of a generally box-shaped main support frame 11, walls forming a combustion chamber 12 in its lower end, a vent chamber =13 at its upper end and opening into a vent stack 14, and a fan and heat exchanger mounting pocket =15 interposed between the combustion chamber 12 and the vent chamber 13. A heat exchange structure 16 is located in the front end of the pocket 15 and provides a series of transversely spaced heat exchange elements 17 extending between and through-connected with the combustion chamber 12 and the vent chamber 13 to establish communication therebetween for discharge of combustion products through the stack 14. The spaces between the heat exchange elements 17 define horizontally extending passages for outflow of space heating air as provided by a blower unit having a composite fan structure designated generally at 18 and located at the rear end of the mounting pocket 15.

The rear of the box-shaped support frame structure 11 is bridged by a vertically elongated flat faced housing subassembly 19 having generally parallel spaced apart outer and inner plates 20 and 21, respectively. The sides of the frame are enclosed by full height side panels 22 and 23 and the front is equipped with vertically spaced horizontally extending louvers 24 (FIG. 3).

The outermost plate 20 of the housing sub-assembly 19 i is: generally rectangular and fully spans the rear of the framing structure to provide for mounting a transformer 25 and an oil burner unit 26 at the rear of the combustion chamber and to provide for mounting of a fan motor 3,109,422 Patented Nov.. 5, 1963 ice 27 at the rear of the pocket 15 with the motor having its shaft centered and rotatably supporting the fan structure 18 in the rear of the pocket 15.

As is best seen in FIG. 2, the inner plate 21 of the housing has a somewhat ovoid outline configuration and tapers smoothly from a large diameter circular region at its upper end to a small diameter circular region at its lower end. The inner plate has a large circular opening 21L at its upper end for mounting a fan orifice ring 28 and a smaller opening 218 at its lower end for mounting an air tube 29 that leads into the combustion chamber 12.

The inner plate 21 is joined to the outer plate 20 in any suitable fashion and a generally arcuate bafile 30 is located at a midheight position therebetween to define a generally annular pressure chamber 3 1 encircling the rear end of the pocket 15' and having a discharge passage leading along a lip or vane 30L depending from one extremity of the baffle. The discharge passage opens into a downwardly tapering chamber 32 communicating with the air tube that leads into the combustion chamber 112. The oil burner unit 26 extends into this air tube and fires into the combustion chamber in the usual way.

The motor 27 is equipped with a cylindrical mounting frame 33 equipped with radial attachment arms 34 secured to the outer plate 20 at spaced points surrounding a large air inlet opening 20A in the upper end of this plate. An oil feed pump 35 is shown as including a mounting frame 36 secured to an end bell of the motor 27 and a coupler 37 connects the pump to the motor shaft. An oil feed line 38 leads from the pump to the oil burner unit 26 and passes through the downwardly tapering chamber 32 of the housing 19. Finally, the ignition wire 39 for the oil burner unit 26 is shown emerging from the side of the transformer 25.

In accordance with this invention, the blower unit 18 which is mounted on the shaft of the motor 27 has a composite fan structure comprised of radially displaced inner and outer fan sections. The inner fan section as illustrated herein for purposes of disclosure has a set of four propeller blades operating in the rear end of the mounting pocket 15 to blow a high volume flow of room air through the passages existing between the heat exchange elements 17. This air takes on heat from the heat exchange elements and is directed appropriately by the louvers 24 to heat the space Within which the heater unit of this invention is mounted. The outer fan section is of a centrifugal blower type and as illustrated herein for purposes of disclosure consists of a mounting ring 40 having a series of integral tabs 40T secured to the propeller tips and provided with a series of transversely oriented radial blades 40B operating in the pressure chamber 31 for creating a supply of pressurized combustion air that flows downwardly through the chamber 32 and then into the air tube 29. The blades being spaced about the exterior of the ring 40 act on a large radius and, therefore, travel at a relatively high peripheral speed to provide a quiet source of high pressure air for the oil burner unit 26.

The concentrically arranged radially displaced fan sections of the blower unit conserve space in the axial direction and while beingdriven from the same motor shaft they serve to provide separate sources of air of dilferent characteristics. Because of their radially displaced mounting arrangement, neither section blocks the required inflow of air of the other and this insures optimum capacity. The use of the same shaft for driving both fan sections and also for driving the pump avoids the need for separate belt driven shafts and all of these features lead to a compact high capacity unitary heater structure.

In the illustrated arrangement, a potential hot spot ex-- structure to form a casing, walls forming a combustion chamber in the lower portion of said casing, a venting passage for said chamber at its upper end and a set of horizontally spaced apart vertically extending heat exchange elements interposed' between said chamber and said passage and establishing communication for discharge of combustion products therethrough, an air tube leading into said chamber, a burner unit mounted to said structure at its lower end and extending into the air tube to fire into said chamber, a blower unit mounted to said structure in facing relation to said heat exchange elements and having an axially directed propeller type inner fan section andan outer centrifugal blower fan section radially outwardly of and fixed on said inner section for rotation jointly therewith, means providing an annular pressure chamber encircling said outer fan section and leading therefrom to said air tube for supplying pressurized combustion air generated by rotation of said outer fan section, and a motor driving said inner fan section to blow heating air horizontally across and between said heat exchangeelements.

2.. The heater arrangement of claim 1 wherein said burner unit is of the oil fired type and wherein an oil pump .for supplying the burner unit is mounted at the rear of said framing structure in line with and connected directly to the fan motor.

3. A unitary heater comprising generally box-shaped framing structure, panels associated with said framing structure to form a casing, walls forming a combustion chamber in the lower portion of said casing, a venting chamber and passage in the upper portion of said casing, and said casing providing a mounting pocket intermediately of and separating said chambers and open from rear to front through said structure, a set of vertically extending heat exchange elements spaced apart laterally in a front region of said pocket and connected to establish internal flow passages between said chambers for discharge of combustion products therethrough, a housing subassembly spanning the rear of said framing structure and providing an opening registering with said pocket and encircled by a generally annular pressure chamber that is open about its, inner margin, said housing subassembly having an internal passage leading vertically therein to establish communication from said pressure chamber to an air tube leading into said combustion chamber at the rear thereof, a burner unit for said combustion chamber mounted to said housing subassembly at its lower end and projecting into said air tube, and a blower unit mounted to said housing subassembly in line with the opening thereof and including a motor at the rear of said subassembly and driving a shaft projecting horizontally forwardly into a rear region of said pocket, an axially directed propeller type inner fan section on said shaft to rotate in the rear of said pocket and blow heating air horizontally through spaces between said heat exchange elements, and an outer centrifugal blower fan section radially outwardly of and attached to the periphery of said inner section to project radially into and move circularly through said annular pressure chamber for supplying pressurized combustion air through said vertical internal passage to said air tube.

4. The heater arrangement of claim 3 wherein said burner unit is of the oil fired type and wherein an oil pump for supplying the burner unit is mounted at'the rear of said framing structure in line with and connected directly to the fan motor.

7 5. A unitary heater comprising generally box-shaped framing structure, panels associated with said framing structure to form a casing, walls forming a combustion chamber in the lower portion of said casing a venting chamber and passage in the upper portion of said casing and said casing providing a mounting pocket intermediately of and separating said chambers and open from rear to front through said structure, a set of vertically extending heat exchange elements spaced apart laterally in a front region of said pocket and connected to establish internal flow passages between said chambers for discharge of combustion products therethrough, a separate horizontally elongated fin joined to and projecting upwardly between lower ends of each adjacent set of heat exchange elements, a housing subassembly spanning the rear of said framing structure and providing an opening registering with said pocket and encircled by a generally annular pressure chamber that is open about its inner margin, said housing subassembly having an internal passage leading vertically therein to establish communication from said pressure chamber to an air tube leading into said combustion chamber at the rear thereof, a burner unit for said combustion chamber mounted to said housing subassembly at its lower end and projecting into said air tube, and a blower unit mounted to said housing subassembly in line with the opening thereof and including a motor at the rear of said subassembly, a horizontal shaft driven by said motor and projecting forwardly into a rear region of said pocket, an axially directed propeller type inner fan section on said shaft to rotate in the rear of said pocket and blow heating air through spaces be tween said heat exchange elements, and an outer centrifugal blower fan section radially outwardly of and attached to the periphery of said inner section to project radially into and move circularly through said annular pressure chamber for supplying pressurized combustion air to said air tube.

6. In a unitary heater that includes a combustion chamber, a venting passage spaced vertically above said chamber, heat exchange elements in laterally spaced vertioally extending position between said chamber and passage and connected for establishing'a flow of combustion products in heat transferring relation through said heat exchange elements, a burner connected into said combustion chamber and blower facilities for supplying heating air across said heat exchange elements and for supplying combustion air to said burner in said combustion chamber, said blower facilities comprising a rotatable shaft'arranged on a horizontal axis projecting toward said heat exchange elements and having a unitary fan assem-. bly mounted thereon and rotatable about the axis of said shaft, said fan assembly comprising an inner axially directed propeller type fan section facing towards said heat exchange elements for blowing heating air horizontally thereacross and having a radially offset outer centrifugal blower fan section encircling said inner section and mounted thereon for movement jointly therewith and means providing an annular pressure chamber encircling said outer fan section and a supply passage leading from said pressure chamber to direct compression air to said burner and said combustion chamber.

7. A unitary heater comprising generally box-shaped framing structure, panels associated with said framing structure to form a casing, walls forming a combustion chamber in the lower portion of said casing and a venttion for discharge of combustion products therethrough,

said heat exchange elements defining therebetween a set of horizontally extending passages for flow of space heating air, with adjacent elements forming a juncture at the lower end of each of the last-named passages, a separate-- horizontally elongated radiator fin projecting upwardly from each juncture, an air tube leading into said chain- 5 ber, a burner unit mounted to said structure at its lower end and extending into the air tube to fire into said chamber, a blower unit mounted to said structure in facing relation to the rear of said heat exchange elements and having an inner fan section for axial discharge of heating air and an outer centrifugal blower fan section for radial discharge of air, said outer fan section being disposed radially outwardly of and fixed on said inner section for rotation jointly therewith, means providing an annular pressure chamber encircling said outer fan section for enabling pressure build up therein of combustion air on rotation of said outer fan section, means carried by said framing structure for leading combustion air from said pressure chamber into said air tube, and a motor mounted at the rear of said framing structure in line with and in rotatable driving connection to said blower unit.

References Cited in the file of this patent UNITED STATES PATENTS 2,205,451 Woolery June 25, 1940 2,590,109 Lindenbaum Mar. 25, 1952 2,788,171 Kulow Apr. 9, 1957 FOREIGN PATENTS 854,876 Great Britain Nov. 23, 1960 

1. A UNITARY HEATER COMPRISING GENERALLY BOX-SHAPED FRAMING STRUCTURE, PANELS ASSOCIATED WITH SAID FRAMING STRUCTURE TO FORM A CASING, WALLS FORMING A COMBUSTION CHAMBER IN THE LOWER PORTION OF SAID CASING, A VENTING PASSAGE FOR SAID CHAMBER AT ITS UPPER END AND A SET OF HORIZONTALLY SPACED APART VERTICALLY EXTENDING HEAT EXCHANGE ELEMENTS INTERPOSED BETWEEN SAID CHAMBER AND SAID PASSAGE AND ESTABLISHING COMMUNICATION FOR DISCHARGE OF COMBUSTION PRODUCTS THERETHROUGH, AN AIR TUBE LEADING INTO SAID CHAMBER, A BURNER UNIT MOUNTED TO SAID STRUCTURE AT ITS LOWER END AND EXTENDING INTO THE AIR TUBE TO FIRE INTO SAID CHAMBER, A BLOWER UNIT MOUNTED TO SAID STRUCTURE IN FACING RELATION TO SAID HEAT EXCHANGE ELEMENTS AND HAVING AN AXIALLY DIRECTED PROPELLER TYPE INNER FAN SECTION AND AN OUTER CENTRIFUGAL BLOWER FAN SECTION RADIALLY OUTWARDLY OF AND FIXED ON SAID INNER SECTION FOR ROTA- 